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1 /* readahead.c - preload files into disk cache.
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2 *
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3 * Copyright 2013 Rob Landley <rob@landley.net>
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4 *
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5 * No standard.
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6
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7 USE_READAHEAD(NEWTOY(readahead, NULL, TOYFLAG_BIN))
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8
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9 config READAHEAD
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10 bool "readahead"
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11 default y
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12 help
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13 usage: readahead FILE...
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14
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15 Preload files into disk cache.
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16 */
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17
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18 #include "toys.h"
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19
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20 #include <sys/syscall.h>
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21
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22 static void do_readahead(int fd, char *name)
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23 {
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24 int rc;
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25
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26 // Since including fcntl.h doesn't give us the wrapper, use the syscall.
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27 // 32 bits takes LO/HI offset (we don't care about endianness of 0).
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28 if (sizeof(long) == 4) rc = syscall(__NR_readahead, fd, 0, 0, INT_MAX);
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29 else rc = syscall(__NR_readahead, fd, 0, INT_MAX);
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30
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31 if (rc) perror_msg("readahead: %s", name);
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32 }
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33
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34 void readahead_main(void)
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35 {
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36 loopfiles(toys.optargs, do_readahead);
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37 }
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